#include <stdlib.h>
#include <termios.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/signal.h>
#include <sys/types.h>
#include <string.h>

#define BAUDRATE B38400
#define MODEMDEVICE "/dev/ttyS1"
#define _POSIX_SOURCE 1         //POSIX compliant source
#define FALSE 0
#define TRUE 1

volatile int STOP=FALSE;

void signal_handler_IO (int status);    //definition of signal handler
int wait_flag=TRUE;                     //TRUE while no signal received
char devicename[80];
long Baud_Rate = 38400;         // default Baud Rate (110 through 38400)
long BAUD;                      // derived baud rate from command line
long DATABITS;
long STOPBITS;
long PARITYON;
long PARITY;
int Data_Bits = 8;              // Number of data bits
int Stop_Bits = 1;              // Number of stop bits
int Parity = 0;                 // Parity as follows:
// 00 = NONE, 01 = Odd, 02 = Even, 03 = Mark, 04 = Space
int Format = 4;
FILE *input;
FILE *output;
int status;

int main(int Parm_Count, char *Parms[])
{
	char version[80] = "       POSIX compliant Communications test program version 1.00 4-25-1999\r\n";
	char version1[80] = "          Copyright(C) Mark Zehner/Peter Baumann 1999\r\n";
	char version2[80] = " This code is based on a DOS based test program by Mark Zehner and a Serial\r\n";
	char version3[80] = " Programming POSIX howto by Peter Baumann, integrated by Mark Zehner\r\n";  
	char version4[80] = " This program allows you to send characters out the specified port by typing\r\n";
	char version5[80] = " on the keyboard.  Characters typed will be echoed to the console, and \r\n";
	char version6[80] = " characters received will be echoed to the console.\r\n";
	char version7[80] = " The setup parameters for the device name, receive data format, baud rate\r\n";
	char version8[80] = " and other serial port parameters must be entered on the command line \r\n";
	char version9[80] = " To see how to do this, just type the name of this program. \r\n";
	char version10[80] = " This program is free software; you can redistribute it and/or modify it\r\n";
	char version11[80] = " under the terms of the GNU General Public License as published by the \r\n";
	char version12[80] = " Free Software Foundation, version 2.\r\n";
	char version13[80] = " This program comes with ABSOLUTELY NO WARRANTY.\r\n";
	char instr[100] ="\r\nOn the command you must include six items in the following order, they are:\r\n";
	char instr1[80] ="   1.  The device name      Ex: ttyS0 for com1, ttyS1 for com2, etc\r\n";
	char instr2[80] ="   2.  Baud Rate            Ex: 38400 \r\n";
	char instr3[80] ="   3.  Number of Data Bits  Ex: 8 \r\n";
	char instr4[80] ="   4.  Number of Stop Bits  Ex: 0 or 1\r\n";
	char instr5[80] ="   5.  Parity               Ex: 0=none, 1=odd, 2=even\r\n";
	char instr6[80] ="   6.  Format of data received:  1=hex, 2=dec, 3=hex/asc, 4=dec/asc, 5=asc\r\n";
	char instr7[80] =" Example command line:  com ttyS0 38400 8 0 0 4 \r\n";
	char Param_strings[7][80];
	char message[90];

	int fd, tty, res, i, error;
	char In1, Key;
	struct termios oldtio, newtio;       //place for old and new port settings for serial port
	struct termios oldkey, newkey;       //place tor old and new port settings for keyboard teletype
	struct sigaction saio;               //definition of signal action
	char buf[255];                       //buffer for where data is put

	input = fopen("/dev/tty", "r");      //open the terminal keyboard
	output = fopen("/dev/tty", "w");     //open the terminal screen

	if (!input || !output)
	{
		fprintf(stderr, "Unable to open /dev/tty\n");
		exit(1);
	}

	error=0;
	fputs(version,output);               //display the program introduction
	fputs(version1,output);
	fputs(version2,output);
	fputs(version3,output);
	fputs(version4,output);
	fputs(version5,output);
	fputs(version6,output);
	fputs(version7,output);
	fputs(version8,output);
	fputs(version9,output);
	fputs(version10,output);
	fputs(version11,output); 
	fputs(version12,output);
	fputs(version13,output);
	//read the parameters from the command line
	if (Parm_Count==7)  //if there are the right number of parameters on the command line
	{
		for (i=1; i < Parm_Count; i++)  // for all wild search parameters
		{
			strcpy(Param_strings[i-1],Parms[i]);
		}
		i=sscanf(Param_strings[0],"%s",devicename);
		if (i != 1) error=1;
		i=sscanf(Param_strings[1],"%li",&Baud_Rate);
		if (i != 1) error=1;
		i=sscanf(Param_strings[2],"%i",&Data_Bits);
		if (i != 1) error=1;
		i=sscanf(Param_strings[3],"%i",&Stop_Bits);
		if (i != 1) error=1;
		i=sscanf(Param_strings[4],"%i",&Parity);
		if (i != 1) error=1;
		i=sscanf(Param_strings[5],"%i",&Format);
		if (i != 1) error=1;
		sprintf(message,"Device=%s, Baud=%li\r\n",devicename, Baud_Rate); //output the received setup parameters
		fputs(message,output);
		sprintf(message,"Data Bits=%i  Stop Bits=%i  Parity=%i  Format=%i\r\n",Data_Bits, Stop_Bits, Parity, Format);
		fputs(message,output);
	}  //end of if param_count==7
	if ((Parm_Count==7) && (error==0))  //if the command line entries were correct
	{                                    //run the program
		tty = open("/dev/tty", O_RDWR | O_NOCTTY | O_NONBLOCK); //set the user console port up
		tcgetattr(tty,&oldkey); // save current port settings   //so commands are interpreted right for this program
		// set new port settings for non-canonical input processing  //must be NOCTTY
		newkey.c_cflag = BAUDRATE | CRTSCTS | CS8 | CLOCAL | CREAD;
		newkey.c_iflag = IGNPAR;
		newkey.c_oflag = 0;
		newkey.c_lflag = 0;       //ICANON;
		newkey.c_cc[VMIN]=1;
		newkey.c_cc[VTIME]=0;
		tcflush(tty, TCIFLUSH);
		tcsetattr(tty,TCSANOW,&newkey);

		switch (Baud_Rate)
		{
			case 38400:
			default:
			BAUD = B38400;
			break;
			case 19200:
			BAUD  = B19200;
			break;
			case 9600:
			BAUD  = B9600;
			break;
			case 4800:
			BAUD  = B4800;
			break;
			case 2400:
			BAUD  = B2400;
			break;
			case 1800:
			BAUD  = B1800;
			break;
			case 1200:
			BAUD  = B1200;
			break;
			case 600:
			BAUD  = B600;
			break;
			case 300:
			BAUD  = B300;
			break;
			case 200:
			BAUD  = B200;
			break;
			case 150:
			BAUD  = B150;
			break;
			case 134:
			BAUD  = B134;
			break;
			case 110:
			BAUD  = B110;
			break;
			case 75:
			BAUD  = B75;
			break;
			case 50:
			BAUD  = B50;
			break;
		}  //end of switch baud_rate
		switch (Data_Bits)
		{
			case 8:
			default:
			DATABITS = CS8;
			break;
			case 7:
			DATABITS = CS7;
			break;
			case 6:
			DATABITS = CS6;
			break;
			case 5:
			DATABITS = CS5;
			break;
		}  //end of switch data_bits
		switch (Stop_Bits)
		{
			case 1:
			default:
			STOPBITS = 0;
			break;
			case 2:
			STOPBITS = CSTOPB;
			break;
		}  //end of switch stop bits
		switch (Parity)
		{
			case 0:
			default:                       //none
			PARITYON = 0;
			PARITY = 0;
			break;
			case 1:                        //odd
			PARITYON = PARENB;
			PARITY = PARODD;
			break;
			case 2:                        //even
			PARITYON = PARENB;
			PARITY = 0;
			break;
		}  //end of switch parity

		//open the device(com port) to be non-blocking (read will return immediately)
		fd = open(devicename, O_RDWR | O_NOCTTY | O_NONBLOCK);
		if (fd < 0)
		{
			perror(devicename);
			exit(-1);
		}

		//install the serial handler before making the device asynchronous
		saio.sa_handler = signal_handler_IO;
		sigemptyset(&saio.sa_mask);   //saio.sa_mask = 0;
		saio.sa_flags = 0;
		saio.sa_restorer = NULL;
		sigaction(SIGIO,&saio,NULL);

		// allow the process to receive SIGIO
		fcntl(fd, F_SETOWN, getpid());
		// Make the file descriptor asynchronous (the manual page says only
		// O_APPEND and O_NONBLOCK, will work with F_SETFL...)
		fcntl(fd, F_SETFL, FASYNC);

		tcgetattr(fd,&oldtio); // save current port settings 
		// set new port settings for canonical input processing 
		newtio.c_cflag = BAUD | CRTSCTS | DATABITS | STOPBITS | PARITYON | PARITY | CLOCAL | CREAD;
		newtio.c_iflag = IGNPAR;
		newtio.c_oflag = 0;
		newtio.c_lflag = 0;       //ICANON;
		newtio.c_cc[VMIN]=1;
		newtio.c_cc[VTIME]=0;
		tcflush(fd, TCIFLUSH);
		tcsetattr(fd,TCSANOW,&newtio);

		// loop while waiting for input. normally we would do something useful here
		while (STOP==FALSE)
		{
			status = fread(&Key,1,1,input);
			if (status==1)  //if a key was hit
			{
				switch (Key)
				{ /* branch to appropiate key handler */
					case 0x1b: /* Esc */
					STOP=TRUE;
					break;
					default:
					fputc((int) Key,output);
					//                  sprintf(message,"%x ",Key);  //debug
					//                  fputs(message,output);
					write(fd,&Key,1);          //write 1 byte to the port
					break;
				}  //end of switch key
			}  //end if a key was hit
			// after receiving SIGIO, wait_flag = FALSE, input is available and can be read
			if (wait_flag==FALSE)  //if input is available
			{
				res = read(fd,buf,255);
				if (res)
				{
					for (i=0; i<res; i++)  //for all chars in string
					{
						In1 = buf[i];
						switch (Format)
						{
							case 1:         //hex
							sprintf(message,"%x ",In1);
							fputs(message,output);
							break;
							case 2:         //decimal
							sprintf(message,"%d ",In1);
							fputs(message,output);
							break;
							case 3:         //hex and asc
							if ((In1) || (In1))
							{
								sprintf(message,"%x",In1);
								fputs(message,output);
							}
							else fputc ((int) In1, output);
							break;
							case 4:         //decimal and asc
							default:
							if ((In1) || (In1))
							{
								sprintf(message,"%d",In1);
								fputs(message,output);
							}
							else fputc ((int) In1, output);
							break;
							case 5:         //asc
							fputc ((int) In1, output);
							break;
						}  //end of switch format
					}  //end of for all chars in string
				}  //end if resɘ
				//            buf[res]=0;
				//            printf(":%s:%d\n", buf, res);
				//            if (res==1) STOP=TRUE; /* stop loop if only a CR was input */
				wait_flag = TRUE;      /* wait for new input */
			}  //end if wait flag == FALSE

		}  //while stop==FALSE
		// restore old port settings
		tcsetattr(fd,TCSANOW,&oldtio);
		tcsetattr(tty,TCSANOW,&oldkey);
		close(tty);
		close(fd);        //close the com port
	}  //end if command line entrys were correct
	else  //give instructions on how to use the command line
	{
		fputs(instr,output);
		fputs(instr1,output);
		fputs(instr2,output);
		fputs(instr3,output);
		fputs(instr4,output);
		fputs(instr5,output);
		fputs(instr6,output);
		fputs(instr7,output);
	}
	fclose(input);
	fclose(output);

	return 0;
}  //end of main

/***************************************************************************
* signal handler. sets wait_flag to FALSE, to indicate above loop that     *
* characters have been received.                                           *
***************************************************************************/

void signal_handler_IO (int status)
{
	//    printf("received SIGIO signal.\n");
	wait_flag = FALSE;
}

